Tape cartridge

Abstract: A tape cartridge comprising; a casing body (101) having at a front portion thereof a pocket (106) for receiving a head of a tape recording/reproduction apparatus when the tape cartridge is loaded in the apparatus, a front lid (108) for covering a front side of the tape extending in the pocket, a back lid (109) for covering a back side of the tape in the pocket, and an upper lid (110) for covering an upper side of the tape in the pocket, the back and upper lids (109,110) being linked to an opening movement of the front lid (108) so that the back and upper lids (109,110) are opened, one of the back and upper lids (109,110) having a hole (124), and another one of the back and upper lids (109,110) having a pin (125) received in the hole (124) so that the back lid (109) is pivotally connected to the upper lid (110), the tape cartridge has a projection wall (131,301) extending substantially parallel to the pin and hole (124,125) for preventing disengagement between the pin and hole (124,125) by an external force (A).

Description: BACKGROUND OF THE INVENTION Field of the Invention This invention relates to a tape cartridge and a recording/reproduction apparatus for the tape cartridge and, more particularly to, a small-scale tape cartridge having a two- or three-lids structure in which a pocket or mouth portion, for receiving a head of the recording/reproduction apparatus upon loading of the cartridge in the recording/reproduction apparatus, is formed in a front portion of a casing body of the tape cartridge, and in which a tape of the tape cartridge extending across the pocket portion is covered with the two or three lids when the cartridge is not loaded. With respect to tape cartridges described in this specification, "front (side)" denotes a side of the tape cartridge facing the head, "upper (side)" denotes a side of the cartridge where the lids are positioned when opened, "transverse (end)", "side" and "left and/or right" correspond to (end) portion or portions of the pocket portion located oppositely in the lengthwise direction of the tape extending in the pocket portion. Description of the Related Art A double-lid or two-lids structure of tape cartridges of this kind, e.g., an 8 mm video tape cartridge shown in Fig. 5, is known which has a front lid 202 capable of opening and closing a front side of a pocket 201, and an inner lid or back or rear lid 205 capable of opening and closing a non-magnetic surface side of a magnetic tape 204 by moving along guide grooves 203 in side walls of the pocket 201. See Japanese Patent Unexamined Publication Nos. 58-128069, 61-210585 and 61-210587, for example. Further, in order to reduce the size of a recording/reproduction mechanism or apparatus for such a tape cartridge, a cylinder/cartridge overlapping system is well known in which, as shown in Fig. 20, a cylindrical head or cylinder with the read/write head 206 of the recording/reproduction apparatus enters the pocket 201 of the cartridge at the time of cartridge loading. See, for example, Japanese Patent Laid-Open Publication Nos. 60-163264 and 60-171684. In this structure, if the cylinder (cylinder drum) 206 is introduced deep into the pocket of the 8 mm video cartridge to an excessively large extent, there is a possibility that the cylinder 206 may interface with a part of the inner or back lid 205, for opening/closing the non-magnetic face side of the tape 204, as shown in Fig. 6. Recently, various technologies have been developed to meet a demand for magnetic recording/reproduction apparatuses such as video cameras (VTRs, i.e., video tape recorders and/or players) smaller in size and weight. In general, the size of a VTR mechanism is determined by shapes of the cylinder and the tape cartridge (cassette). Accordingly, for reduction in the size of the mechanism, it is necessary to reduce the size(s) of the cylinder and/or the cartridge. Therefore, attempts have been made to reduce the diameter of the cylinder by increasing the rotational speed and/or increasing the tape winding angle and other measures and to develop a compact cassette (cartridge) having an external size smaller than that of the digital audio tape (DAT) cassette. It is desirable to solve beforehand the above-mentioned problem of contact or interferece between the cylinder and the inner lid so as to enable to use such a new cartridge. In a conventional tape cartridge as shown in Figs. 5 and 6, the inner lid 205 having an upper lid portion 207 serving as an upper lid and a back lid portion 208 serving as a back lid is brought into substantial contact with an upper surface 210 of a cartridge casing body 209, when the inner lid 205 is in an open state, as shown in Fig. 6. Accordingly, a cartridge pressing portion 212 of transport or transfer means 211, which moves the tape cartridge in a direction of arrow A to a predetermined position in the recording/reproduction apparatus at the time of loading of the cartridge in the apparatus, presses the casing body 209 in the direction A at a position thereof on the back or rear side (in a direction B) of the inner lid 205 set in the open position. However, the inventors of the present invention have found out that there is a risk of failure to appropriately press the cartridge casing body 209 in the direction A by such pressing if the cartridge is smaller. Japanese Patent Examined Publication No. 63-16825 discloses a triple-lids type of tape cartridge in which, as shown in Fig 7, front and back surfaces of a tape 204 are covered with a front lid 215 and a back lid 216 while an upper side of a pocket 201 is covered with an upper lid 217. The front lid 215 moves upwardly around pivots 218 to upwardly open relative to a casing body 209. The upper lid 217 is connected to the front lid 215 by connecting pins 219. The upper lid 217 is moved obliquely upwardly to move onto an upper surface 210 of the casing body 209 in response to the upward pivotal movement of the front lid 215. The back lid 216 is connected to the upper lid 217 by connecting pins 220. Slide pins 221 provided on lower wall portions of the back lid 216 are moved and guided along guide grooves 222 in side walls of the pocket 201. In the open state of the lids 215, 216, 217, the back lid 216 is moved above the pocket 201 to the upper surface 210 of the casing body 209 to be laid generally parallel to the upper surface 210. In a structure having three members, i.e., front lid 215, back lid 216 and upper lid 217 pivotally connected to each other in this manner, the lids 215, 216, and 217 retract in such a manner as to be laid on each other in the open state. In this manner, the amount of forward projection of the cover lids 205 to 207 at the upper positions in the open state can be reduced. However, a front end 223 of the back lid 216 is positioned so as to cover an upper portion of the pocket 201. Therefore, a compact component arrangement cannot be adopted in which the magnetic head of the tape recording/reproduction apparatus is introduced deep into the pocket 201. Accordingly, the effect of reducing the overall size of the recording/reproduction apparatus is limited. Also in the case of the conventional tape cartridge constructed as shown in Fig. 7, the upper lid 217 is brought into contact with the upper surface 210 of the casing body 209, and a cartridge pressing portion of a cartridge transport or transfer means should be, therefore adapted to press the casing body 209 at the back or rear side, i.e., in the direction B, of the upper lid 217 in the open state. When the tape cartridge of Fig. 7 is in the lids-closing state, left and right side ends of the back lid 216 are supported at four points through the upper connecting pins 220 and the lower slide pins 221, where a wall portion 231 of the back lid 216 has a shape of longer dimension or size in the widthwise direction of the cartridge and shorter dimension or size in the direction of thickness of the cartridge. Therefore, if an external force C is applied to the back lid 216 so as to press the back lid 216 obliquely upwardly, for example, by an inadvertent operation of a user, the wall portion 231 of the back lid 216 is deformed in a flexural manner toward the front of the casing body 209, as indicated by an imaginary or double-dot-dash line in Fig. 22. In such a case, there is a possibility that the connecting pin(s) 220 will come off the associated pin hole(s) with the deformation of the lid wall 231. To avoid such a situation, the inventors have considered the axial length of the connecting pins 220 and the depth of the associated pin holes fitted around the connecting pins 220 may be increased. In practice, however, the operation of assembling these components becomes difficult if engagement structure having an increased fitting depth is adopted. SUMMARY OF THE INVENTION It is the object of the present invention to provide a tape cartridge of a triple lid structure having front, back and upper lids and arranged to prevent connected portions of the back and upper lids from being accidentally disengaged. To achieve this object, according to the present invention, there is provided a tape cartridge having the features of appended claim 1. In a preferred embodiment of this tape cartridge of the invention, the front lid is supported on left and right side walls of the casing body through second connecting pivot means so as to open upwardly by moving pivotally on the second connecting pivot means, and the front lid is biased by a spring to a closing position thereof. The upper lid has an upper wall for covering the upper side of the pocket, and left and right arms projecting from left and right ends of the upper wall and extending along outer surfaces of the side walls of the casing body. A front portion of the upper lid and an upper portion of the front lid are pivotally connected to each other through third connecting pivot means. The casing body has horizontal guide grooves in the outer surfaces of its side walls so as to extend slightly upwardly and toward the rear end of the casing body, and vertical guide grooves in inner surfaces of side wall portions defining two sides of the pocket. Slide shafts on rear end portions of the arms of the upper lid are fitted in and engaged with the horizontal guide grooves of the casing body so as to move along the horizontal guide grooves. Slide pins on a lower rear portion of the back lid are fitted in and engaged with the vertical guide grooves of the casing body so as to move upwardly and obliquely toward a rear portion of the casing body. For example, the first connecting pivot means are provided on the back lid so as to project transversely outwardly while the associated holes are provided in the upper lid. If in this case an external force acts on the back lid in the closed state so that the back lid is pushed toward the front end of the casing body, there is a possibility that the first connecting pivot means will come off the holes without the coming-off prevention walls. However, since the coming-off prevention walls are protrusively formed on front peripheral portions of the holes, the first connecting pivot means are received by the coming-off prevention walls to be maintained in the same position. Accordingly, if the external force is removed, the first connection pivot means are fitted in the holes again by being guided along the coming-off prevention walls, thereby maintaining the connecting state. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of an overall internal construction of a three lid cartridge; Fig. 1A is a perspective view of the cartridge shown in Fig. 1; Fig. 2 is a longitudinal side-sectional view of a preferred modification of the tape cartridge shown in Fig. 1; Fig. 2A is an enlarged perspective view of a part E, i.e. XVIA, of Fig. 2; Fig. 3 is a plan view of a part of the cartridge shown in Fig. 2; Fig. 4 is a longitudinal side-sectional view, in an opened state of three lids, of the cartridge shown in Fig. 2; Fig. 5 is a longitudinal side-sectional view, in a lid-closing state, of a part of a conventional 8 mm video tape cartridge; Fig. 6 is a longitudinal side-sectional view, in a lid-opening state, of the part of the conventional 8 mm video tape cartridge shown in Fig. 5; Fig. 7 is a longitudinal side-sectional, in of a lid-opening state, of a part of another conventional 8 mm tape video cartridge; and Fig. 8 is a longitudinal side-sectional view, in a lid-closing state, of the part of the conventional 8 mm video tape cartridge shown in Fig. 7. DESCRIPTION OF THE PREFERRED EMBODIMENTS Figs. 1 and 1A show a video tape cartridge having a lid opening/closing mechanism in accordance with another embodiment of the present invention. Referring to Figs. 1 and 1A, a pair of hubs 102 around which a tape 103 is wound are provided in left and right positions inside a casing body 101. The tape 103 drawn out from one of the hubs 102 is guided by tape guides 105 provided at tape lead-out openings 104 formed in left and right front portions of the casing body 101 and is wound around the other hub 102. A pocket 106 for tape loading is formed at a central part of a front portion of the casing body 101, i.e., between the left and right tape lead-out openings 104. The pocket 106 is open at its upper, lower and front sides. To protect the tape 103 and to prevent dust from sticking to the tape 103 when the tape 103 is not used, a portion of the tape 103 extending through a front section of the pocket 106 is covered with a front lid 108, a back lid 109 and an upper lid 110, each formed of a plastic mold member, at the time of unloading of the cartridge. Referring then to Fig. 1A the front lid 108 has a major wall 111 which closes the front side of the casing body 101 including the open front side of the pocket 106 over the entire width of the casing body 101, and side walls 112 extending rearwardly from the left and right ends of the major wall 111. Connecting pivots 113 are formed in opposing positions on inner surfaces of the side walls 112 to project inwardly. The side walls 112 of the front lid 108 are fitted to outer surfaces of front end portions of left and right side walls 101c of the casing body 101, with the connecting pivots 113 fitted to pivot holes formed in the front end portions of the side walls 101c, thereby enabling the front lid 108 to move pivotally on the connecting pivots 113 to open upwardly. The front lid 108 is biased in a direction to pivotally close by a torsion coil spring fitted around one of the connecting pivots 113. The upper lid 110 has a flat upper wall 116 which closes the upper side of the pocket 106. A pair of left and right arms 117 are formed on left and right ends of the upper wall 116 so as to project rearwardly along outer surfaces of the side walls 101c of the casing body 101. The upper lid 110 is opened and closed according to the opening/closing movement of the front lid 108. For this linkage, connecting pivots 118 are formed on front portions of the left and right arms 117 of the upper lid 110 to project transversely inwardly. The connecting pivots 118 are fitted to connecting holes in upper left and right portions of the front lid 108. Further, slide shafts 120 are formed on rear-ends of inner surfaces of the arms 117 and are fitted in and engaged with horizontal guide grooves 121 in the outer surfaces of the side walls 101c of the casing body 101. The horizontal guide grooves 121 extend in the front-rear direction of the cartridge and have front-end portions sloped down toward their front ends. The upper wall 116 of the upper lid 110 have left and right cut-out portions 123 corresponding to (upper walls of) the tape lead-out openings 104. This connection structure enables the upper lid 110 to move forwardly and rearwardly between the closing position, at which the upper wall 116 closes the upper side of the pocket 106 continuously with the front lid 108, and the opening position shown in Fig. 14, to which the upper wall 116 retracts from the upper side of the pocket 106 by moving toward a rear portion of the casing onto the upper surface of the upper wall of the casing body 101. Since the upper wall 116 is formed with the cut-out portions 123, it does not interfere with the upper walls of the tape lead-out openings 104 when the upper lid 110 is opened or closed, even though the arms 117 of the upper lid 110 are formed continuously with the left and right ends of the upper wall 116. It is therefore possible for the upper lid 110 to move smoothly to open or close the upper side of the pocket 106. The back lid 109 is formed of a plate slightly bent as viewed in a cross section perpendicular to the transverse direction of the case body 101. The back lid 109 has connecting pins 125 protrusively formed on its left and right ends of an upper end portion thereof. The back lid 109 is connected to the upper lid 110 by fitting the connecting pins 125 into holes in bosses 126 on inner surfaces of the upper wall 116 of the upper lid 110. The back lid 109 also has leg portions 127 projecting from rear surfaces of its lower left and right portions. Slide pins 128 provided on the leg portions 127 are movably engaged with and fitted in S-shaped vertical guide grooves 129 formed in the left and right side walls of the pocket 106 so as to extend slantingly and upwardly away from the front end of the casing body 101. This connection structure enables the back lid 109 to move between a closing position at which the back lid 109 faces the reverse or rear side of the tape 103 in the pocket 106 and an opening position at which the back lid 109 is situated horizontally on the upper surface of the upper wall of the casing body 101 after moving onto the same. Figs. 2, 2A, 3, and 4 show a modification of the video tape cartridge having the lid opening/closing mechanism in accordance with the present invention. In the arrangement shown in Figs. 2 to 4, bosses 126 are protrusively formed on the inner surface of the upper wall 116 of the upper lid 110 at left and right end positions closer to the rear end of the upper wall 116 so as to face each other. The connecting pins 125 of the back lid 109 are pivotally fitted in pin holes 124 of the bosses 126 while the wall of the back lid 109 is deformed in a flexural manner, thereby connecting the upper lid 110 and the back lid 109 so chat the upper lid 110 and the back lid 109 can move pivotally on each other. In the lid closing state, the front lid 108 covers the outer side of the tape 103 led out to a front portion of the casing body 101, the upper lid 110 covers the upper side of the pocket 106, and the back lid 109 covers the tape 103 on the back side of the same in the pocket 106. If, in this state, an external force A is applied forwardly and upwardly to the rear surface of the back lid 109 as shown in Fig. 3, there is a risk of the wall of back lid 109 being deformed in a flexural manner until the connecting pins 125 come off the pin holes 124. In the tape cartridge shown in Figs. 2 to 4, coming-off prevention walls 131 are formed on the upper lid 110 to maintain the connected state even in such situation. As shown in Figs. 2 and 2A, each coming-off prevention wall 131 has a curved wall with C-shaped section. The wall 131 is formed only on a front half portion of a peripheral portion around the pin hole 124. In the tape cartridge shown in Figs. 2 to 4, if an external force A such as that mentioned above acts on the back lid 109 to push the upper lid 110 toward the front end of the casing body 101, there is also a possibility of the connecting pivots 118 coming off the connecting holes of the front lid 108. To minimize this possibility, a stopper wall 132 is further formed on the upper end of the front lid 108 to contact the front end of the upper wall 116 of the upper lid 110. That is, the stopper wall 132 receives the upper wall 116 to prevent the upper lid 110 from being moved in the forward direction of the casing body 101 by external force A. In the example shown in Fig. 2 to 4, in the portions of the back lid 109 and the upper lid 110 connected to each other, the coming-off prevention wall 131 is protrusively formed on the front half of the peripheral portion of each of the pin holes 124 in which the connecting pins 125 are fitted. In this arrangement, even if the connecting pins 125 are urged to come off the pin holes 124 by a flexural deformation of the wall of the back lid wall 109, the connecting pins 125 are received and stopped by the coming-off prevention walls 131. Thus, the risk of disengagement of the back lid 109 from the upper lid 110 is reduced, so that the durability of the tape cartridge can be improved. Moreover, since the fitting length of the connecting pins 125 and the pin holes 124 need not be increased excessively, the lids 109, 110 can easily be assembled by bending one of the back lid 109 and the upper lid 110 slightly. The coming-off prevention walls 131 may have any other cross-sectional shapes, such as the shape of "V" or a trapezoidal shape, instead of the illustrated shape of "C", as long as the forward movement of the pins 125 can be inhibited. The arrangement may alternatively be such that connecting pins 125 are provided on the upper lid 110 while pin holes 124 are formed in the back lid 109. In such a case, coming-off prevention walls 131 may be provided, for example, on the rear side of the connecting pins 125 in order to inhibit the corresponding movement of the back lid 109 in the direction A or a forward direction relative to the upper lid 110.

Claims: A tape cartridge comprising: a casing body (101) having a front portion thereof a pocket (106) for receiving a head of a tape recording/reproduction apparatus when the tape cartridge is loaded in the apparatus, a front lid (108) for covering a front side of the tape extending in the pocket, a back lid (109) for covering a back side of the tape in the pocket, and an upper lid (110) for covering an upper side of the tape in the pocket, the back and upper lids (109, 110) being linked to an opening movement of the front lid 8108) so that the back and upper lids (109, 110) are opened, one of the back and upper lids (109, 110) having a hole (124), and another one of the back and upper lids (109, 110) having a pin (125) received in the hole (124) so that the back id (109) is pivotally connected to the upper lid (110), characterized in that the tape cartridge has a projection wall (131) as a part of the pin and hole construction extending substantially parallel to the pin and hole (124, 125) for preventing disengagement between the pin and hole (124, 125) by a force (A) exerted on the back lid and directed obliquely outwardly and upwardly. A tape cartridge according to claim 1, characterized in that the pin (125) is provided on the upper lid (110), the hole (124) and the projection wall (131) are provided on the back lid (109), and the projection wall (131) is formed protrusively on a back side of the pin (125) to inhibit a movement of the back lid (109) by the external force (A). A tape cartridge according to claim 1, characterized in that the hole (124) and the projection wall (131) are provided on the upper lid (110), the pin (125) is provided on the back lid (109), and the projection wall (131) is formed protrusively on a front side of the pin (125) to inhibit a movement of the back lid (109) by the external force (A). A tape cartridge according to claims 2 or 3, characterized in that the projection wall (131) is formed protrusively on a peripheral portion of the hole (124). A tape cartridge according to claim 1, characterized in that the projection wall and pin (125) are provided on the back lid (109), the hole (124) is provided on the upper lid (110), and a part of the upper lid (110) surrounding the hole (124) is arranged between the projection wall and the pin (125). A tape cartridge according to claim 4, characterized in that the projection wall (131) extends continuously from the hole (124).

Inventors: MAEHARA YOSHIMI, MASUDA KENMEI, MIZUTANI HIKARU, NISHIJIMA TATSUMI, OGIRO KENJI, TAKEDA HIDEKAZU, MAEHARA,YOSHIMI, MASUDA,KENMEI, MIZUTANI,HIKARU, OGIRO,KENJI, TAKEDA,HIDEKAZU, MASUDA,KENMEI,, NISHIJIMA TATSUMI,
Applicants: HITACHI LTD, HITACHI MAXELL, HITACHI MAXELL, LTD., HITACHI, LTD.
Application year: 1994
Main classification: G11B23
IPC codes: G11B23, G11B15